Sermorelin Dosage Guide: Trial Data, Half-Life, Dosage Chart & Reconstitution

Sermorelin at a glance

What it is

Sermorelin acetate, the synthetic 29-amino-acid N-terminal fragment of human growth-hormone-releasing hormone - written GHRH(1-29)NH2. Research in the early 1980s established that the first 29 residues retain full activity at the receptor, making this the shortest fully functional GHRH fragment.

Regulatory history

FDA-approved twice: sermorelin injection under NDA 19-863 in 1990 for diagnostic use, and Geref under NDA 20-443 in 1997 for paediatric growth hormone deficiency. Geref was withdrawn by its manufacturer in 2008 for commercial reasons - a small diagnostic market - and not because of a safety finding or a recall.

Mechanism

A GHRH-receptor agonist on anterior-pituitary somatotrophs, prompting release of the body's own growth hormone. Because it acts upstream of GH itself, normal somatostatin negative feedback stays intact - a genuine mechanistic distinction from administering growth hormone directly.

The dose with data behind it

30 micrograms per kilogram per day, subcutaneously at bedtime, in growth-hormone-deficient children. That is the regimen from the published multicentre trial, and it is the only sermorelin dose with controlled efficacy data attached to it.

What that trial found

In 110 previously untreated prepubertal GH-deficient children, height velocity rose from 4.1 +/- 0.9 cm/yr at baseline to 8.0 +/- 1.5 at six months and 7.2 +/- 1.3 at twelve. 74% were classed as good responders at six months.

The comparison nobody quotes

In a three-arm trial of 60 children, six-month height velocities were 9.2 cm/yr on GHRH(1-29) at 30 mcg/kg/day, 9.3 on 60 mcg/kg/day, and 14.6 on growth hormone at 0.1 IU/kg/day. Growth hormone was significantly superior (p < 0.01), and doubling the GHRH dose achieved nothing.

The immunogenicity finding

In that same trial, nearly all participants in both GHRH groups developed antibodies to GHRH. This is rarely mentioned on commercial pages and is a real characteristic of sustained administration.

Half-life

Very short and properly measured: an initial phase of about 1.9 +/- 0.2 minutes and an elimination phase of about 10.4 +/- 0.2 minutes for GHRH(1-29)NH2. Native GHRH is around 4.3 minutes. Minutes, not hours.

Research-market status

No approved sermorelin product is currently marketed in the United States for the uses discussed here. Material sold as a lyophilised research vial is not an approved medicine and is supplied for research and educational use only.

Reported ranges from research/community — examples, not recommendations.

What it is / mechanism

Sermorelin is the first 29 amino acids of human growth-hormone-releasing hormone, amidated at the C-terminus - GHRH(1-29)NH2. Native GHRH is 44 residues long, and work in the early 1980s established that biological activity at the receptor lives entirely in the first 29. Everything beyond residue 29 can be removed without losing potency, which is what makes sermorelin the shortest fully functional fragment of the parent hormone rather than a partial agonist or an analogue with altered pharmacology. It binds the GHRH receptor on somatotroph cells of the anterior pituitary, the same receptor the body's own GHRH uses, and triggers the synthesis and pulsatile release of endogenous growth hormone. The mechanistic argument made for this class - and it is a real argument, not marketing - is that acting upstream preserves the regulatory architecture. Growth hormone release remains subject to somatostatin's inhibitory tone and to the negative feedback that IGF-1 exerts, so the pituitary can still refuse. Administering recombinant growth hormone bypasses all of that and delivers a fixed amount regardless of what the feedback loops would have preferred. That preserved feedback is the mechanistic selling point and it is also, in practice, the ceiling. A drug that asks the pituitary to release growth hormone cannot exceed what the pituitary is able and willing to release. When the head-to-head trial described in the evidence section put GHRH(1-29) against growth hormone itself, growth hormone won decisively - and the mechanism predicts exactly that, because one arm was constrained by the patient's own regulatory system and the other was not. The same feature that makes the approach physiologically elegant limits how much it can do. The pituitary also has to be capable of responding, which defines who the compound can work for. Sermorelin's approved paediatric indication was growth hormone deficiency of hypothalamic origin - children whose pituitary was intact but whose hypothalamic GHRH signal was inadequate. In someone whose pituitary somatotrophs are themselves damaged or absent, a GHRH agonist has nothing to act on. This is also why the compound found an early role as a diagnostic agent: a GHRH challenge distinguishes hypothalamic from pituitary causes of deficiency by testing whether the pituitary can respond when properly asked. Sermorelin's pharmacology is dominated by how quickly it disappears. The measured elimination half-life is around ten minutes, with an initial distribution phase closer to two. That is a genuinely short exposure - the molecule is present as a signal, not as a sustained drug level - and it is the reason the trial regimen was a single daily subcutaneous injection given at bedtime rather than a continuous or divided schedule. Bedtime administration aligns the pulse the drug provokes with the body's own largest natural GH pulse, which occurs during early slow-wave sleep. The compound is not maintaining a level; it is adding an impulse to a rhythm that already exists. Within the GHRH family, sermorelin is the unmodified parent fragment. Tesamorelin adds a trans-3-hexenoyl group at the N-terminus to slow degradation, and CJC-1295 in its no-DAC form - also called Mod GRF 1-29 - carries four amino-acid substitutions for the same purpose. All three act at the same receptor, which is why combining them with each other is redundant, while pairing any of them with a ghrelin-receptor agonist such as ipamorelin is not.

Researched effects

Sermorelin's effect profile is better documented than almost anything else in this market, because it was studied in controlled trials for an approved indication. The honest summary is that it works, and that it worked less well than the alternative. The pivotal evidence comes from a multicentre trial in 110 previously untreated prepubertal children with growth hormone deficiency, 86 of whom were evaluable for efficacy, given 30 micrograms per kilogram per day subcutaneously at bedtime for up to a year. Height velocity rose from a baseline of 4.1 +/- 0.9 cm per year to 8.0 +/- 1.5 at six months, settling to 7.2 +/- 1.3 at twelve months. At six months, 74% of the children were classed as good responders. Bone age advanced proportionately rather than prematurely - the ratio of change in bone age to change in height age was 1.04 +/- 0.58, not significantly different from unity (p = 0.63), which matters because a growth treatment that accelerates skeletal maturation faster than height gain can reduce final adult stature. There were no adverse biochemical or hormonal changes, no excessive IGF-1 generation and no disturbance of fasting glucose. That is a real, positive, controlled result: roughly a doubling of growth rate in the first six months, with a favourable bone-age profile and clean biochemistry. The comparison that puts it in perspective is a separate three-arm trial of 60 children, and it is the study commercial pages do not cite. Twenty children received GHRH(1-29) at 30 mcg/kg/day, twenty received 60 mcg/kg/day, and twenty received growth hormone at 0.1 IU/kg/day. At six months, mean height velocities were 9.2, 9.3 and 14.6 cm per year respectively. Growth hormone was significantly superior to either GHRH dose (p < 0.01). The authors concluded that GHRH was unlikely to be as effective as growth hormone for promoting growth in this population. Two details inside that result matter more than the headline. First, doubling the dose from 30 to 60 mcg/kg/day produced essentially no additional growth - 9.2 against 9.3 cm/yr. The dose-response curve for this compound was flat across a two-fold range, which is direct evidence for a ceiling imposed by pituitary capacity rather than by how much drug is given. Second, nearly all participants in both GHRH groups developed antibodies to GHRH. IGF-1 rose initially during GHRH treatment and then declined back toward baseline over the study, a pattern consistent with a response that attenuates rather than sustains. Adverse effects were minimal - three patients reported mild injection-site irritation. The attenuation and antibody findings are the single most useful things to know about sustained sermorelin administration, and they are almost entirely absent from commercial material about the compound. Every figure above was generated in growth-hormone-deficient children being measured for linear growth, which is a different population and a different endpoint from the adult use the research market is interested in. That does not mean the adult record is empty, and this page used to say it was. Two placebo-controlled University of Washington trials gave the same molecule to healthy older adults at 14 mcg/kg (about 1 mg) in a single evening injection - NCT00000380 on age-related sleep impairment, and a six-month trial in 89 adults that reported improved WAIS-R performance IQ and several other cognitive measures against placebo (PMID 16399214). The investigators' own review describes both as covering GH profiles, body composition and functional status including sleep, cognition and physical function. So sleep, body composition and cognition in adults have been tested against placebo; what has not been tested is whether any of that translates into the recovery and anti-ageing outcomes the market talks about, and none of the paediatric numbers above describes an adult. Nothing here is a claim that sermorelin treats, prevents or improves any condition, and nothing here is medical advice.

Dosage — reported ranges (overview)

Sermorelin is one of the few compounds in this market where a dose can be quoted with a trial behind it, and where that trial dose is markedly larger than what the market actually uses. The dose with controlled efficacy data is 30 micrograms per kilogram per day, given subcutaneously at bedtime. That is the regimen from the 110-child multicentre trial, and the head-to-head study used the same figure alongside a 60 mcg/kg/day arm. Weight-scaling that to an adult is arithmetic rather than evidence: 30 mcg/kg on a 70 kg person computes to roughly 2.1 mg per day. Commonly reported research-market figures are in the range of about 100 to 500 micrograms at bedtime - somewhere between a quarter and a twentieth of the scaled trial figure. That gap deserves to be stated carefully rather than turned into a recommendation. Weight-scaling a paediatric dose to an adult is not a validated method; the trial population were children with diagnosed growth hormone deficiency and an intact but under-stimulated hypothalamic-pituitary axis, measured for linear growth over months, and none of those conditions applies to an adult with a normal axis. The honest conclusion is not that adults should use more.\n\nThere is, however, an adult dose with controlled data behind it, and it is not the scaled paediatric figure. The two placebo-controlled University of Washington trials in healthy older adults - NCT00000380 on age-related sleep impairment, and the six-month cognition trial in 89 adults at PMID 16399214 - both used a single evening subcutaneous injection of 14 micrograms per kilogram, roughly 1 mg. That is about half the paediatric 30 mcg/kg and about half the 2.1 mg the scaling arithmetic produces, and it is the figure to compare the market range against: 100 to 500 micrograms is a fifth to a tenth of the dose those adult trials actually gave. No published study identifies 100 to 500 micrograms as a threshold of activity for any endpoint. The flat dose-response in the head-to-head trial is the more useful finding for anyone thinking about dose size. Doubling from 30 to 60 mcg/kg/day moved six-month height velocity from 9.2 to 9.3 cm/yr - which is to say, not at all. A GHRH agonist is asking the pituitary for growth hormone, and past a certain point the pituitary's capacity, not the size of the request, sets the answer. Dose escalation on this compound has a published null result behind it, which is more than can be said for most peptides. The timing convention is genuinely well-founded, and it is one of the few pieces of community practice that matches the trial protocol exactly. The pivotal study dosed at bedtime, and the reasoning is physiological: the largest natural growth hormone pulse of the day occurs during early slow-wave sleep, so a compound with a ten-minute half-life is best placed to amplify a pulse that is about to happen anyway. With that clearance rate, timing is not a refinement - it is most of the strategy. The attenuation finding should temper expectations of long continuous use. IGF-1 rose initially in the GHRH arms and then declined back toward baseline, and nearly all patients developed anti-GHRH antibodies. Whatever the mechanism, the trial record describes a response that does not simply persist unchanged with continued administration. Everything above describes trial regimens and reported practice for educational purposes. It is not a protocol, not a recommendation, and not medical advice. No approved sermorelin product is currently marketed in the United States for these uses.

A printable protocol sheet with a reconstitution reference and an injection log comes with All-Access Lifetime.

Reconstitution — bac-water math

Sermorelin ships as a lyophilised powder, commonly in 5 mg vials, and is reconstituted with bacteriostatic water before any amount can be drawn. The arithmetic is fixed: concentration in mg per mL equals the vial's milligram content divided by the millilitres of bacteriostatic water added, and syringe units equal (target amount / concentration) x 100, since a 1 mL U-100 insulin syringe is graduated into 100 units. Because this compound is dosed in micrograms while vials are labelled in milligrams, the conversion to keep straight is that 1 mg is 1,000 mcg - so a 5 mg vial holds 5,000 mcg. The dosage chart below works a 5 mg vial at four volumes against 200 mcg and 500 mcg examples. One practical point falls out of it and is worth stating: at 1 mL of diluent, a 200 mcg example measures just 4 units on the syringe, which is a very small distance on the scale and hard to draw accurately. Adding more bacteriostatic water does not change how much peptide is in a dose - it spreads that dose across more syringe graduations, which is why the more dilute preparations are easier to measure precisely for a compound dosed this small. These are arithmetic examples, not recommendations. The calculator on this page runs the same computation for any vial size and volume.

This is concentration math, not a dose recommendation.

Injection / administration basics

The trial route was subcutaneous injection given once daily at bedtime, and that is also the route described in reported practice. General handling concepts - aseptic technique, rotation between injection sites, and consistent timing relative to sleep - are covered here as general educational information. Because the compound is dosed in micrograms from a vial labelled in milligrams, the measurement step carries more room for error than it does for compounds dosed in whole milligrams, which is the practical reason the dilution choice in the chart above matters. The detailed workflow comes with All-Access Lifetime, which includes the printable protocol sheet and injection log for every compound. Nothing here is a personal administration protocol or an instruction to administer anything to a person.

Half-life & frequency rationale

Sermorelin's half-life is short, and unlike most peptides in this market it has actually been measured. Published pharmacokinetics for GHRH(1-29)NH2 report a two-phase profile: an initial phase of about 1.9 +/- 0.2 minutes and an elimination phase of about 10.4 +/- 0.2 minutes. For context, native 44-residue GHRH is reported at around 4.3 +/- 1.4 minutes, and GRF analogues as a class are described as having plasma half-lives of roughly 10 to 20 minutes in humans. These are minutes, not hours, and that single fact explains most of how the compound is used. Sermorelin is not maintaining a plasma level; it delivers a brief signal to the pituitary and is gone. The growth hormone pulse it provokes outlasts the peptide that caused it, which is why a once-daily injection of something with a ten-minute half-life is a coherent regimen rather than an obvious mismatch. It also explains why the entire GHRH analogue class was engineered the way it was. The published record shows researchers making single-residue substitutions specifically to extend this number - a D-Ala2 substitution raises it from about 4.3 to about 6.7 minutes, and later work on PEGylation and albumin conjugation pursued the same goal more aggressively. Tesamorelin's N-terminal hexenoyl group and CJC-1295's four substitutions are commercial expressions of the same engineering problem. Sermorelin is the unmodified baseline that all of those were trying to improve on, which means its short duration is not a flaw in a particular product but the native property of the parent molecule. The practical consequence is that timing dominates. With a ten-minute elimination phase, when the injection is given matters far more than it would for a compound lasting hours, and the bedtime convention - aligning the provoked pulse with the natural nocturnal one - is the trial protocol rather than folklore.

Stacking — overview

Sermorelin's combination logic follows directly from its receptor pharmacology, and it produces one clear rule. Combining sermorelin with another GHRH analogue - tesamorelin, or CJC-1295 in either form - is redundant, because all of them act on the same GHRH receptor and are competing for the same pathway rather than adding to it. Pairing it with a ghrelin-receptor agonist such as ipamorelin is the combination that has a mechanistic rationale, because a GHRH agonist and a GHRP act at two different receptors on the same cell, and the reported effect of combining the two classes is more than either produces alone. That rationale is genuine pharmacology, though it should be noted that the reported multiples circulating in community sources are not controlled figures. Mechanism-level detail on each combination, and the combination-specific cautions, are covered in the paid Sermorelin Stacking Module included with this guide.

For how combinations are grouped by research context, the named blends, and why a pre-mixed blend vial cannot be calculated from its total milligrams, see the peptide stacks guide.

Storage & handling

• Lyophilised and unopened: store cold; the dry powder is the stable form and tolerates shipping without refrigeration for short periods.
• Reconstituted: refrigerate at roughly 2-8 degrees Celsius and protect from light. Commonly cited usable windows of a few weeks are handling conventions rather than stability data measured for this peptide.
• Avoid repeated freeze-thaw cycles, and direct the bacteriostatic water down the vial wall rather than shaking - GHRH fragments are handled as fragile peptides.
• Wipe the vial stopper with alcohol before each entry; the benzyl alcohol in bacteriostatic water inhibits bacterial growth but does not replace aseptic technique.

Evidence File

The Sermorelin Evidence File: Two Corrected Numbers and an Empty Registry

Sermorelin is one of the very few compounds in this market with genuine controlled trial data behind it, which makes the quality of the secondary reporting around it unusually important. This module goes back to the primary records: the fetched abstracts of every paediatric trial the free guide cites, the two pharmacokinetic papers behind the half-life figures that travel with this compound everywhere, and a full ClinicalTrials.gov sweep run on 2026-08-26 with each query named so it can be rerun. Two of the most widely repeated pharmacokinetic attributions turn out to belong to a different species and a different molecule. The registry result is not what the search page appears to show, and the compound's own name reaches only a fraction of its own literature.

• 2 pharmacokinetic figures re-attributed to their real source
• 4.3 minutes: the human half-life, measured in 10 normal men
• 39 of 40 children developed anti-GHRH antibodies in six months
• No registered therapeutic sermorelin trial, of any status

Sourcing File

The Sermorelin Sourcing File: The Substitution No Certificate Can See

Most certificate-of-analysis guidance is generic, because most peptides fail in generic ways. Sermorelin does not. Its nearest research-market neighbour is a stereoisomer that shares its molecular formula and its monoisotopic mass to every decimal place, which means the two lines a buyer normally trusts most on a certificate cannot separate them. This module builds the compound-specific numbers a certificate has to be read against: the identity block re-derived from the sequence rather than copied, the electrospray ion series, the acetate and moisture arithmetic worked against a labelled vial, the degradation peaks this particular sequence produces, and a line-by-line read of a constructed certificate.

• 0 daltons separate sermorelin from its D-Ala2 stereoisomer
• 2023: the first published separation of the two
• 1.8 to 6.7 percent of a salt-form label is counter-ion
• 3 deamidation sites and 1 oxidation site in 29 residues

Benefit & Outcome Review

The Sermorelin Benefit and Outcome Review: Every Adult Claim, Traced to Its Document

The free guide establishes that sermorelin's efficacy data come from growth-hormone-deficient children measured for linear growth. This module asks the question that leaves open: what adult data exist, and where do the circulating adult numbers actually come from? The adult record turns out to be larger than any search on the compound's own name can show - part of it is placebo-controlled, ran for months, and is filed under a name that does not include this compound at all. Each circulating claim is then followed back to the document it originates in, and those documents are described by study type, species, molecule and what was actually measured. Several turn out to be about something other than sermorelin. One contains no data at all, one contains an experiment its own abstract never mentions, and one review hands this molecule another molecule's trial.

• 2 placebo-controlled adult trials, invisible to any search on the compound name
• 2 mg nightly for 6 weeks: DEXA found no change in muscle or fat
• 3 secretagogues at once, on testosterone, in the 14-man chart review
• 1 editorial with no methods and no patients underpins the adult case

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